package com.itheima.controller;

import com.itheima.result.R;

import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.multipart.MultipartFile;

import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletResponse;

import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;

import java.util.UUID;

/**
 * @author father
 * @date 2021/12/5
 * @apiNote 文件上传和下载
 **/
@RestController
@Slf4j
@RequestMapping("/common")
public class CommonController {
    @Value("${jeje.path}")
    private String basePath;

    @PostMapping("/upload")
    public R<String> upload(MultipartFile file) {
        String originalFilename = file.getOriginalFilename();
        String suffix = originalFilename.substring(originalFilename.lastIndexOf("."));
        String filename = UUID.randomUUID().toString() + suffix;
        File dir = new File(basePath);
        //注释掉if，第一次请求个数有问题，应该只有一个上传请求，但是还出现了下载请求，估计是前端的问题
        if (!dir.exists()) {
            dir.mkdirs();
        }
        try {
            file.transferTo(new File(basePath + filename));
        } catch (IOException e) {
            e.printStackTrace();
            return R.error("上传图片失败！");
        }
        return R.success(filename);
    }

    @GetMapping("/download")
    //因为需要下载图片显示在网页上，所以需要传入response对象得到它的流对象写到页面上，如果是下载成附件，保存为硬盘的文件。。。
    public void download(String name, HttpServletResponse response) {
        try {
            FileInputStream stream = new FileInputStream(new File(basePath + name));
        ServletOutputStream outputStream = response.getOutputStream();
        response.setContentType("image/jpeg");
        int len = 0;
        byte[] bytes = new byte[1024];
        while ((len = stream.read(bytes)) != -1) {
            outputStream.write(bytes, 0, len);
            outputStream.flush();
        }
        outputStream.close();

            stream.close();
        } catch (IOException e) {
            e.printStackTrace();
        }

    }

}
